Under Construction.

www.google.com/googlevoice/about.html
Go to Google Voice

Google Voice gives you a single phone number that rings all of your phones, saves your voicemail online, and transcribes your voicemail to text. Other cool features include the ability to listen in on messages while they're being left, block unwanted callers, and make cheap international calls.

Features:
Set up profile for which phone to ring based on caller or time of day
Voicemail transcription (works sometimes)
Call from Google voice website - It will call you then connect you with the called party.
SMS forwarding to email
Unlimited Free Calling with Google Voice - Google Docs
www.google.com/googlevoice/about.html
Getting Started with Google Voice - Google Voice Help
www.google.com/support/voice/bin/topic.py?topic=29353
My Tips:
To change settings- add a phone ... 1. Sign in to Google Voice. 2. Click the gear icon at the top of the page. gear icon 3. Click Voice settings. 4. Select the Phones tab. "Add another phone" is at the bottom. Change Settings: 5. Click the Edit button under the phone for which you want to set a ring schedule. 6. Click the Show advanced settings link. 7. In the Ring Schedule section, select your option using the radio buttons. To make sure a phone doesn't ring at a specific time of the day, select Use custom schedule and enter your time range. 8. Click Save at the bottom of the page. To set up a call to dial: Go to Google Voice (www.google.com/voice/) Click Call Specify a name in your contact list or a number to call Specify phone to call with. If you specify Google Talk you must have a gmail window open. The google talk page says it doesn't work on a Mac, but it uses google chat instead.
Problems:
1. Dialed number and heard ringing from my calling phone, but the called phone didn't ring until 3 rings, at the same time the called phone rang I got a message to leave a voice mail.
There was just a dial tone on called phone.
This happens randomly.

2. It will only ring a phone for 25 seconds before going to voice mail. This setting cannot be changed.
The answering service on my home line is set to 4 rings (30 seconds) before going to voice mail, so it never goes to the voice mail on my home phone, unless I reduce the number of rings.

Links:
Sign in/sign up (www.google.com/voice/)
Make Free VoIP Calls from Google Voice using a sipgate number.
Unlimited Free Calling with Google Voice - Google Docs
Christina Trapolino comments on her Google Voice experiment - Google+
Google Voice Quick Reference Cheatsheet v2.0 Speeds Through Phone Menus
Google Voice at Google Docs

last updated 1 Apr 2012